1. Field of the Invention
The present invention relates generally to contour measuring probes for coordinate measuring machines (CMMs); and more particularly to a contour measuring probe using a relatively small measuring force for contact-type contour measuring devices.
2. Discussion of the Related Art
Manufactured precision objects such as optical components (for example, aspherical lenses) and various industrial components need to be measured to determine whether manufacturing errors of the objects are within acceptable tolerance. Such manufacturing errors are the differences between the design dimensions of the object and the actual dimensions of the manufactured object. Measured dimensions of the manufactured object are usually regarded as the actual dimensions. A precision measuring device is used to measure the objects; and the more precise the measuring device, the better. Generally, the precision objects are measured with a CMM, which has a touch trigger probe that contacts the objects. A measuring force applied to the touch trigger probe of the coordinate measuring machine should be small. If the measuring force is too great, a measuring contact tip of the touch trigger probe may be easily damaged thereby causing a measuring error.
As indicated above, a contact-type coordinate measuring device is commonly used to measure dimensions of precision objects such as optical components and certain industrial components. A relatively large measuring force is provided to the touch trigger probe by the coordinate measuring device. However, if the object has a slanted surface, the contact tip of the touch trigger probe may become bent or deformed by a counterforce acting on the touch trigger probe, thereby causing a measuring error. Therefore, the touch trigger probe is not ideal for measuring precision lenses having slanted surfaces.
Therefore, a contour measuring probe employing a relatively small measuring force is desired.